Despite being adjacent to one another, these lines are now essentially separate railways that do not interact with one another after they pass through the Bermondsey Dive Under on the approach to London Bridge. This instils resilience in to the network that was not there previously – when there is a problem on one set of lines, the knock impact on other lines is reduced. This is important in such a congested stretch of railway.
Dedicated lines and platforms also means the space available for Thameslink services through London Bridge has been hugely increased in peak hours – from one train per hour before work started compared to up to sixteen per hour by the end of the programme.
Recycling the heritage
Wherever possible, existing structures were reused, to minimise disruption and reduce waste. Although some old viaducts had to be replaced by modern structures, they have been designed to remain in keeping with the older architecture, with the new arches having a similar form compared to the existing masonry arches.
This also ensured that the load distribution on the original foundations remained relatively unchanged, allowing for many of the existing piers to be reused. This contributed significantly to reducing the number of new foundation structures required, meaning the work could be completed quicker, at a lower cost and with less disruption from heavy construction work.
A sustainable legacy
The Thameslink Programme is committed to increasing net positive biodiversity on its projects. Prior to construction, the site had a low conservation value and limited botanical diversity.
The soil was heavily contaminated with hydrocarbons and asbestos, as well as the invasive species Japanese Knotweed. The project saw the eradication of the Japanese Knotweed and the removal of over 21,900 tonnes of contaminated material. Furthermore, wildflower planting and the installation of 765 square metres of green walls has increased the site’s biodiversity and helped the team achieve a CEEQUAL score of 96.6%, having increased biodiversity in the area by 113%.
The team also carried out extensive community engagement, including upgrading the garden in the Lewisham Community Centre, refurbishing a youth club in a local church and volunteering on the XLP youth charity bus.
Southwark Park station
During the work to demolish a number of the existing viaducts, Thameslink Programme engineers discovered the ghostly remains of a long-lost South London railway station which closed more than 100 years ago.
Southwark Park station, perched on a viaduct above Rotherhithe New Road, only served passengers from 1902 to 1915 before it closed for good. The old ticket hall, booking hall and platforms were revealed, with the arch which held the booking hall retained.